Propshaft assembly with center bearing shield

ABSTRACT

A propshaft assembly that includes first and second shaft members, a joint, a center bearing assembly and a deflector. The joint couples the first and second shaft members to one another. The center bearing assembly includes a bearing that supports the joint. The deflector is coupled to the joint and shields an axial side of the bearing.

FIELD

The present invention generally relates to a propshaft assembly with acenter bearing shield.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Motorized vehicles traditionally include a power supply (e.g. aninternal combustion engine, an electric motor and/or a combinationthereof) that produces a drive torque. A transmission receives the drivetorque and employs gear ratios to modify the input torque to obtainvarious desired output torques. The output torque is then transmittedthrough a propshaft assembly to a rear differential unit, which evenlydistributes the torque between a pair of axle shafts. The axle shafts,in turn, cause movement of the vehicle through the vehicle wheels.

The propshaft assembly is subject to the stresses of the torquetransmitting over its length. A center bearing assembly coupled to thevehicle's chassis assists in allowing rotation of and support for thepropshaft assembly. However, the propshaft assembly and, specifically,the center bearing assembly are exposed to various contaminants, such asdirt, water, oil, salt, etc., due to their location at an undersurfaceof the vehicle. These contaminants can effect the bearing performance.

It would, therefore, be desirable to provide a propshaft assembly withprotection from contaminants for the center bearing assembly.

SUMMARY

This section provides a general summary of some aspects of the presentdisclosure and is not a comprehensive listing or detailing of either thefull scope of the disclosure or all of the features described therein.

In one form, the present teachings provide a propshaft assembly thatincludes a first shaft member, a second shaft member, a bearingassembly, a universal joint and a deflector. The first shaft member isconfigured to be coupled to a first power transmitting component. Thesecond shaft member is configured to be coupled to a second powertransmitting component. The bearing assembly has a support, which isconfigured to be coupled to a vehicle structure, and a bearing. Theuniversal joint couples the first and second shaft members to oneanother. The universal joint has a joint structure that is received intothe bearing such that the bearing supports the joint structure forrotation about an axis of the bearing. The deflector has an annular bodyportion that is mounted on the joint structure. The body portion extendsradially outwardly from the joint structure and tapers axially towardthe bearing assembly with increasing radial distance from the axis ofthe bearing. The body portion terminates at a radially outwardly edgethat is disposed axially apart from the support by a predetermined gapdistance. The deflector and the support cooperate to form a labyrinththat shields the bearing on a first axial side.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples in this summary are intended for purposes ofillustration only and are not intended to limit the scope of the presentdisclosure, its application and/or uses in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only and arenot intended to limit the scope of the present disclosure in any way.The drawings are illustrative of selected teachings of the presentdisclosure and do not illustrate all possible implementations. Similaror identical elements are given consistent identifying numeralsthroughout the various figures.

FIG. 1 is a schematic illustration of a motor vehicle with a propshaftassembly constructed in accordance with the teachings of the presentdisclosure;

FIG. 2 is a perspective view of the propshaft assembly of FIG. 1;

FIG. 3 is a cross-sectional view of a portion of the propshaft assemblyof FIG. 1;

FIG. 4 is a front view of the center bearing shield of FIG. 3;

FIG. 5 is a sectional view of the center bearing shield taken throughplane 5-5 in FIG. 4;

FIG. 6 is an enlarged view of a portion of the propshaft assembly ofFIG. 1 showing a center bearing shield and a spline yoke in accordancewith the teachings of the present disclosure; and

FIG. 7 is a cross-sectional view of another portion of the propshaftassembly of FIG. 1.

DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

With reference to FIG. 1 of the drawings, a propshaft assemblyconstructed in accordance with the teachings of the present invention isgenerally indicated by reference numeral 10. A motor vehicle 12 caninclude a powertrain 14 as part of the vehicle 12 with alongitudinally-mounted engine 16 rotatably driving a crankshaft 18 toprovide rotary power to a transmission 20. The powertrain 14 can outputrotary power to a rear axle assembly 22, via the propshaft assembly 10.The rear axle assembly 22 distributes the rotary power to a pair ofvehicle wheels 24 (only one shown) via axle shafts 26 (only one shown)to propel the vehicle 12. It should be noted that while the rear-wheeldrive vehicle 12 is illustrated, the teachings of the present disclosureare applicable to other vehicle arrangements, such as, for example,all-wheel drive vehicles. Additionally, the propshaft assembly 10 mayreceive the rotary power from any number of components other than thetransmission 20, such as, for example, a torque transfer device, a powertransfer unit or a transfer case.

Referring now to FIG. 2, the propshaft assembly 10 may include a firstshaft member 28, a second shaft member 30, a third shaft member 31, afirst joint 32, a first center bearing assembly 33, a second joint 34and a second center bearing assembly 35. The first shaft member 28 canbe coupled to an output of the transmission 20 in any desired manner,such as a joint 36 (e.g. universal joint or constant velocity joint)that can employ a shaft connection 38. Likewise, a joint 40 (e.g.universal joint or constant velocity joint) can couple the third shaftmember 31 to an input pinion 42 (FIG. 1) associated with the rear axleassembly 22 (FIG. 1) in any desired manner, such as via a flangeconnection 41.

With reference now to FIG. 3, the first joint 32 can be any type ofjoint for rotatably coupling the first and second shaft members 28 and30 to one another, such as a cardan joint, a constant velocity joint, aHooke's joint, or a universal joint. For example, the first joint 32 canhave a joint structure 43 that includes a stub shaft 44 and a cardanjoint 46 for coupling the first and second shaft members 28 and 30 toone another. The stub shaft 44 can include a first coupling portion 48,an annular shaft portion 50, and a second coupling portion 52. The firstcoupling portion 48 can be fixedly coupled to the first shaft member 28.The shaft portion 50 can be disposed axially between the first andsecond coupling portions 48 and 52 and can include a first shoulder 54and a second shoulder 56 between which a generally cylindrical body isdisposed. The second coupling portion 52 can be configured to permit thecardan joint 46 to be removably coupled to the stub shaft 44. In theexample provided, the second coupling portion 52 includes a splinedshaft 58 and a threaded end 60.

The cardan joint 46 can include first and second yokes 62 and 64,respectively and a bearing assembly 66, which can include a conventionalcross-shaped trunion or spider 68 and a plurality of bearing assemblies70. The plurality of bearing assemblies 70 can be mounted on the ends ofthe spider 68 and received in corresponding holes 72 formed in the firstand second yokes 62 and 64. The first and second yokes 62 and 64 can becoupled to the stub shaft 44 and the second shaft member 30,respectively. In this way, the spider 68 can be disposed between thefirst and second yokes 62 and 64 to transmit rotary power therebetween.

In the example provided, the first yoke 62 includes a female-splinedaperture 74 that matingly engages a plurality of axially extendingsplines 75 of the splined shaft 58 of the second coupling portion 52. Anut 76 can be threadably engaged to the threaded end 60 of the stubshaft 44 to fixedly couple the first yoke 62 thereto.

It will be appreciated that the first coupling portion 48 of the stubshaft 44 and the second yoke 64 of the cardan joint 46 can be coupled tothe first and second shaft members 28 and 30 in any desired manner, suchas by welding. Moreover, it will be appreciated that if desired, thefirst joint 32 may be reversed relative to the first and second shaftmembers 28 and 30, such that the cardan joint 46 is directly coupled tothe first shaft member 28 and the stub shaft 44 is directly coupled tothe second shaft member 30.

The joint structure 43 of the first joint 32 can be received into thecenter bearing assembly 34 so as to support the joint structure 43 forrotation about an axis A. In the example provided, the center bearingassembly 34 can be configured to support the stub shaft 44 for rotationand can include a bearing 78, a support 80, a mounting bracket 82, aresilient mount 84, and a deflector 86. The bearing 78 can be a sealedbearing and can include an inner race 88, an outer race 90, and aplurality of bearing elements, such as bearing balls 92, between theinner and outer races 88 and 90, and seal structures 93. Each of theseal structures 93 can form a seal between the inner race 88 and theouter race 90 on an associated side of the bearing 78. The inner race 88can be press-fit onto the shaft portion 50 of the stub shaft 44 andabutted against the first shoulder 54 so as to rotatably support thestub shaft 44.

The support 80 can include the mounting bracket 82, the resilient mount84, an annular frame 94, which can be disposed concentrically about thebearing 78, and a pair of legs 96 (FIG. 2) that can extend outwardlyfrom the frame 94. The legs 96 can be either directly or indirectlycoupled to the vehicle 12 through any means known in the art, forexample only, through fasteners (not shown) coupled to the vehicle'schassis (not shown).

The support 80 can be an annular structure that can be press-fit to theouter race 90 of the bearing 78. The resilient mount 84, which can beformed of a suitable elastomeric material, can be disposed between theannular frame 94 and the mounting bracket 82 to resiliently mount thebearing 78 to the support 80. In the particular example provided, theresilient mount 84 is a thermal plastic elastomer that is molded betweenand permanently bonded to the annular frame 94 and the mounting bracket82.

With reference to FIGS. 3-5, the deflector 86 may include an annular,frusto-conically shaped body portion 98, a collar portion 100, and aplurality of radially extending ribs 102. The collar portion 100 and theplurality of radially extending ribs 102 can be integrally formed withthe annular body portion 98. The collar portion 100 can be mounted onthe first yoke 62 and positioned proximate the bearing 78, such that arelatively small axial space S is disposed between the annular frame 94of the support 80 and a radially outward edge 104 of the annular bodyportion 98. In the particular example provided, the collar portion 100is said to engage a deflector mount surface 106 on the first yoke 62 ina press-fit manner. It will be appreciated that other coupling means canbe employed for coupling the deflector 86 to the first yoke 62,including adhesives, solder, brazing, welding, and mechanical fasteners(e.g., screws, cups).

The annular body portion 98 may extend radially outwardly from thedeflector mount surface 106 of the first yoke 62 and taper axiallytoward the center bearing assembly 34 with increasing radial distancefrom the axis A. The radially extending ribs 102 may extend in asubstantially arcuate shape from a side 108 of the annular body portion98 opposite the center bearing assembly 34 so as to form vanes. Theannular body portion 98 and the radially extending ribs 102 mayterminate at the radially outward edge 104, so as to dispose thedeflector 86 radially apart from the annular frame 94 by a predeterminedgap distance D.

The deflector 86 may cooperate with the support 80 to form a labyrinthfor shielding an axial side of the bearing 78 from contaminants. Thefrusto-conical configuration of the deflector 86, along with the arcuateshape of the radially extending ribs 102 can drive contaminants flowingin towards the bearing 78 in a radially outward direction when thevehicle (FIG. 1) is driven in a forward direction. In this way,contaminants are forced away from the bearing 78 rather thanaccumulating at the interface between the bearing 78 and the shaftportion 50.

With reference to FIG. 7, the second joint 34 and the second centerbearing assembly 35 can be generally similar to the first joint 32 (FIG.3) and the first center bearing assembly 34 (FIG. 3) except as noted.Briefly, the second joint 34 can be any type of joint for rotatablycoupling the second and third shaft members 30 and 31 to one another,such as a cardan joint, a constant velocity joint, a Hooke's joint, or auniversal joint. In the example provided, the second joint 34 can besimilar to the first joint 32 (FIG. 3) and can include a stub shaft 44,which can be coupled to the third shaft member 31, and a cardan joint 46having first and second yokes 62 and 64, respectively and a bearingassembly 66 that can couple the second shaft member 30 to the stub shaft44 in a manner that is similar to that which is described above andillustrated in FIG. 3 for the connection of the cardan joint 46 to thestub shaft 44.

The second center bearing assembly 35 can be configured to support thestub shaft 44 of the second joint 34 for rotation and can be generallysimilar to the first center bearing assembly 34 (e.g., it can include abearing 78, a support 80, a mounting bracket 82, a resilient mount 84,and a deflector 86) except that the deflector 86 can be mounted on anannular portion 200 of the stub shaft 44 that forms the first shoulder54.

With reference to FIGS. 4, 5 and 7, the annular body portion 98 of thedeflector 86 can extend radially outwardly from the annular portion 200of the stub shaft 44 and taper axially toward the center bearingassembly 35 with increasing radial distance from the axis A. The collarportion 100 can be mounted on a deflector mount surface 106′ on the stubshaft 44 and positioned proximate the bearing 78 such that a relativelysmall axial space S′ is disposed between the annular frame 94 of thesupport 80 and a radially outward edge 104 of the annular body portion98. In the particular example provided, the collar 110 engages thedeflector mount surface 106′ in a press-fit manner. It will beappreciated that other coupling means can be employed for coupling thedeflector 86 to the stub shaft 44, including adhesives, solder, brazing,welding, and mechanical fasteners (e.g., screws, cups).

The deflector 86 of the present disclosure can be effective as a shieldthat protects the bearing 78 from contact with dust, moisture, dirt,stones and other debris when the motor vehicle 12 (FIG. 1) is propelledin a predetermined direction (e.g., forwardly). Material impinging onthe deflector 86 can be slung from the deflector 86 due to centrifugalforce. It will be appreciated that the radially extending ribs 102 canstiffen the deflector 86 so that it is less susceptible to impact damage(e.g., from a stone). The deflector 86 of the present disclosure may beconfigured to generate a flow of air during rotation of the deflector 86that could tend to deflect dust, dirt, stones and debris from impingingupon the deflector 86. Such air flow may also be employed to coolportions of the associated center bearing assembly (e.g., center bearingassembly 35). If desired, small holes may be formed into the annularbody portion 98 proximate the root of the radially extending ribs 102 topermit air to be drawn through the deflector 86 from a side opposite theside 108.

It will be appreciated that the above description is merely exemplary innature and is not intended to limit the present disclosure, itsapplication or uses. While specific examples have been described in thespecification and illustrated in the drawings, it will be understood bythose of ordinary skill in the art that various changes may be made andequivalents may be substituted for elements thereof without departingfrom the scope of the present disclosure as defined in the claims.Furthermore, the mixing and matching of features, elements and/orfunctions between various examples is expressly contemplated herein,even if not specifically shown or described, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one example may be incorporated intoanother example as appropriate, unless described otherwise, above.Moreover, many modifications may be made to adapt a particular situationor material to the teachings of the present disclosure without departingfrom the essential scope thereof. Therefore, it is intended that thepresent disclosure not be limited to the particular examples illustratedby the drawings and described in the specification as the best modepresently contemplated for carrying out the teachings of the presentdisclosure, but that the scope of the present disclosure will includeany embodiments falling within the foregoing description and theappended claims.

1. A propshaft assembly comprising: a first shaft member that is adaptedto be coupled to a first power transmitting component; a second shaftmember that is adapted to be coupled to a second power transmittingcomponent; a bearing assembly having a support, which is adapted to becoupled to a vehicle structure, and a bearing; a joint coupling thefirst and second shaft members to one another, the joint having a jointstructure that is received into the bearing such that the bearingsupports the joint structure for rotation about an axis of the bearing;and a deflector having an annular body portion that is mounted on thejoint structure, the body portion extending radially outwardly from thejoint structure and tapering axially toward the bearing with increasingradial distance from the axis of the bearing, the body portionterminating at a radially outwardly edge that is disposed axially apartfrom the support by a predetermined gap distance, the deflector and thesupport cooperating to form a labyrinth that shields the bearing on afirst axial side.
 2. The propshaft assembly of claim 1, wherein thedeflector includes a plurality of radially extending ribs that areformed on the body portion.
 3. The propshaft assembly of claim 2,wherein the radially extending ribs extend from a side of the bodyportion opposite the bearing.
 4. The propshaft assembly of claim 2,wherein the radially extending ribs have an arcuate shape.
 5. Thepropshaft assembly of claim 1, wherein the joint structure includes astub shaft and a cardan joint, the stub shaft including a first shaftportion that is fixedly coupled to one of the first and second shaftmembers, the cardan joint being coupled to the other one of the firstand second shaft members, the cardan joint having a spline yoke that isnon-rotatably coupled to the stub shaft.
 6. The propshaft assembly ofclaim 5, wherein the stub shaft includes a second shaft portion having aplurality of axially extending splines and wherein the spline yokeincludes a female splined aperture into which the second shaft portionis received.
 7. The propshaft assembly of claim 6, wherein a deflectormount is formed on the spline yoke and wherein the deflector is mountedon the deflector mount.
 8. The propshaft assembly of claim 7, whereinthe body portion of the deflector is press-fit to the deflector mount.9. The propshaft assembly of claim 1, wherein the support includes aframe, which is disposed about the bearing, and a resilient mount thatis disposed between the frame and the bearing.
 10. The propshaftassembly of claim 9, wherein the support further comprises a pair oflegs that are coupled to the frame.
 11. The propshaft assembly of claim1, wherein the bearing is a sealed bearing having seal structures, aninner bearing race and an outer bearing race, each of the sealstructures forming a seal between the inner bearing race and the outerbearing race on an associated side of the bearing.
 12. A propshaftassembly comprising: a first shaft member that is adapted to be coupledto a first power transmitting component; a second shaft member that isadapted to be coupled to a second power transmitting component; a jointdisposed between and rotatably coupling the first and second shaftmembers, the joint having a stub shaft and a cardan joint, the stubshaft including a first shaft portion that is fixedly coupled to thefirst shaft member, the cardan joint including a first yoke member,which is non-rotatably coupled to the stub shaft, and a second yokemember that is coupled to the first yoke member and non-rotatablycoupled to the second shaft member; a bearing assembly having a bearing,which is mounted on the stub shaft, and a support into which the bearingis received; and a deflector having an annular body portion and aplurality of ribs, the body portion being mounted on one of the stubshaft and the first yoke member and and extending radially outwardlytherefrom, the body portion having a frusto-conical shape, the ribsbeing integrally formed with the body portion and extending on a side ofthe body portion opposite the bearing, the deflector cooperating withthe support to shield an axial side of the bearing.
 13. The propshaftassembly of claim 12, wherein the bearing is a sealed bearing havingseal structures, an inner bearing race and an outer bearing race, eachof the seal structures forming a seal between the inner bearing race andthe outer bearing race on an associated side of the bearing.
 14. Thepropshaft assembly of claim 13, wherein the ribs have an arcuate shape.15. The propshaft assembly of claim 14, wherein the stub shaft includesa first splined feature that is matingly engaged with a second splinedfeature on the first yoke member.
 16. The propshaft assembly of claim15, wherein the body portion of the deflector is press-fit to the one ofthe stub shaft and the first yoke member.
 17. The propshaft assembly ofclaim 16, wherein the support includes a frame, which is disposed aboutthe bearing, and a resilient mount that is disposed between the frameand the bearing.
 18. The propshaft assembly of claim 17, wherein thesupport further comprises a pair of legs that are coupled to the frame.